GB2440214A

GB2440214A - Thixotropic perfume formulation

Info

Publication number: GB2440214A
Application number: GB0614393A
Authority: GB
Inventors: Nigel Cooper
Original assignee: Thornton and Ross Ltd
Current assignee: Thornton and Ross Ltd
Priority date: 2006-07-20
Filing date: 2006-07-20
Publication date: 2008-01-23
Also published as: GB0614393D0

Abstract

The present invention provides a formulation for spray application to a surface. The formulation comprises greater than or equal to about 1 % w/w of a perfume compound and a sufficient amount of a thixotrope such that the formulation, once applied to the surface, exhibits negligible creep. The thixotrope is preferably selected from xanthan gum, veegum, a polyacrylate compound or silicon oxide. The formulation may further contain at least one of a detergent, a solubiliser, a biocide and a dye. Also disclosed is a method for producing the formulation and the use of the formulation for slow release of the perfume compound contained in the formulation.

Description

PERFUME FORMULATION

The present invention relates to a formulation containing a perfume compound, a method for producing the formulation and the use of the formulation.

Various spices and floral extracts have long been used to impart a perfume, fragrance or the like to the surrounding environment to mask an undesirable odour or to release a more pleasant odour over an extended period of time, such as a few days, weeks or months.

Many industrial and household products have been developed which contain a perfume for slow or controlled release to the surrounding environment.

An example of such a product is a scented candle which is positioned at an appropriate position and then lit to melt the candle wax and thereby vaponse and release the volatile perfume compound(s) held in the wax. A similar product employs a wick in contact with a liquid formulation containing a perfume compound. When the wick is lit the perfume compound retained within the wick is vaporised and released to the surrounding environment. There are however significant safety issues surrounding the use of products which employ a naked flame and such products can be difficult or inconvenient to use.

More recently, products have been developed for slow or controlled release of a perfume in which a liquid containing the perfume compound is warmed by the passage of an electric current through a heating wire in contact with the liquid. Some more elaborate products also incorporate an electrically powered fan to help disperse the perfume to the surrounding environment. A problem with such plug-in' type products is that they require a constant electricity power supply to function and so consume a not insignificant amount of power over the lifetime of the product.

Moreover, the housing in which the heated liquid is contained is susceptible to heating which has the potential to harm a user during and after use. It may also be inconvenient to have to dedicate an electricity power socket to use of the product.

A problem common to products employing a naked flame and products that use electrical heating is that they may be used only in specific areas within a given space.

The former products can only be used in relatively open, well ventilated areas in which it is safe to leave a naked flame and the latter products can be used only in areas in which electricity power sockets are provided. Moreover, both products, as well as similar products that do not rely on heating to release the perfume, are typically bulky and can be difficult to locate where desired within a particular space.

The flexibility of use of such products is therefore significantly restricted.

The object of the present invention is to obviate or mitigate one or more of the above problems.

According to a first aspect of the present invention there is provided a formulation for spray or "squirt" application to a surface, the formulation comprising greater than or equal to about 1 % w/w of a perfume compound and a sufficient amount of a thixotrope such that the formulation, once applied to the surface, exhibits negligible creep.

The present invention thus provides a simple and convenient means for applying any desired amount of a perfume formulation to a specific location from which the perfume is released. The formulation of the present invention is eminently suitable to be spray applied to the inner surface of a waste receptacle or bin to facilitate the slow or controlled-release of the perfume from within the receptacle or bin. The formulation is also suitable for "squirt" application on to a surface ("squirt" application is similar to the manner in which toothpastes are typically dispensed).

As will be appreciated by the skilled person, creep is the plastic deformation of a material resulting from the application of stress over a period of time. In the present circumstances it will be appreciated that in order for the formulation to stay substantially in the location in which it is applied the fonnulation applied to the surface should exhibit negligible creep, i.e. the amount to which the formulation deforms across the surface during the period of time over which the perfume is to be released should be so small as to be unimportant or insignificant. Preferably the formulation, once applied to the surface, exhibits substantially no creep, and more preferably the formulation, once applied to the surface, exhibits no creep. It will be appreciated that where the formulation of the present invention is intended to be used on relatively horizontal surfaces the formulation should exhibit negligible creep in the same way that it should exhibit negligible creep when applied to an inclined or substantially upright or vertical surface.

A second aspect of the present invention provides a slow release perfume formulation for spray or "squirt" application to a surface, the formulation comprising greater than or equal to about 1 w/w of a perfume compound and a sufficient amount of a thixotrope such that the formulation, once sprayedl"squirted" on to the surface, exhibits negligible creep.

A third aspect of the present invention provides a method for producing a formulation for spray or "squirt" application to a surface, the formulation comprising greater than or equal to about 1 % w/w of a perfume compound and a sufficient amount of a thixotrope such that the formulation, once applied to the surface, exhibits negligible creep, wherein the method comprises combining greater than or equal to about 1 % w/w of the perfume with said sufficient amount of the thixotrope to provide said formulation.

A fourth aspect of the present invention provides a method for providing a slow release perfume formulation on a surface, wherein the method comprises spraying or "squirting" the formulation according to the first or second aspect of the present invention on to the surface such that the formulation forms a gel on the surface, the gel being of sufficiently high viscosity so that the formulation on the surface exhibits negligible creep.

A fifth aspect of the present invention provides use of the formulation according to the first or second aspect of the present invention for the slow release to a surrounding environment of the perfume compound comprised in the formulation.

In each of the above aspects of the present invention the surface to which the formulation is applied is preferably the surface, most preferably the inner surface, of a receptacle or container, such as a waste receptacle or bin.

The amount of perfume compound in the formulation determines, at least in part, the strength of the odour emitted by the formulation and the period of time over which the odour can be detected. Thus, the formulation may comprise any appropriate amount of one or more perfume compounds. Preferably the formulation comprises greater than or equal to about 2 % w/w of the perfume compound. It is preferred that the formulation comprises about 1 to 20 % w/w of the perfume compound, more preferably about 2 to 15 % w/w of the perfume compound.

The formulation of the present invention may include any desirable fragrancing material(s) such as, but not limited to, the following perfume compounds. The perfume compound in the formulation of the invention is preferably selected from the group consisting of a synthetic fragrance compound, a green fragrance compound, a floral fragrance compound, a herbal spice fragrance compound and an oriental fragrance compound. The synthetic fragrance compound may be an aldehyde, ketone, ester, alcohol or terpene. The green fragrance compound may be natural or synthetic. Natural sources of the green fragrance compound include galbanum and violet leaf oil. The floral fragrance compound may be an extract of jasmine, rose, lilac and/or lily of the valley. The herbal spice fragrance compound may be derived from lavender, cedar, cloves, cinnamon, moss, sandalwood and/or sage. The oriental fragrance compound may be isolated from an animal material, such as musk. The formulation may comprise one or more of the aforementioned perfume compounds blended together in any desirable ratio.

In order to provide the formulation of the present invention with the desired creep properties the formulation should comprise an appropriate amount of thixotrope. As is well known in the art, a thixotrope is a substance or combination of substances which cause a formulation comprising the thixotrope to exhibit decreased viscosity when subjected to an increased shear force. Thus, a thixotropic formulation, such as the formulation of the present invention, exhibits lower viscosity when under increased shear (such as when being sprayed) than when standing on a surface. In this way, by appropriate selection of the type and amount of thixotrope, the formulation of the present invention can exhibit adequately low viscosity to be sprayed on to a specific location on a surface via a conventional trigger or pump spray applicator and also exhibit sufficiently higli viscosity so that, when provided on the surface (even a substantially upright or vertical surface, such as the inner wall of a container or receptacle) the formulation exhibits negligible creep.

It is preferred that the formulation comprises greater than or equal to about 0.05 % w/w of the thixotrope, more preferably greater than or equal to about 0.1 % w/w of the thixotrope. Yet more preferably the formulation comprises about 0.05 to 5 % w/w of the thixotrope. Most preferably the formulation comprises about 0.05 to 2 % w/w of the thixotrope.

The thixotrope is preferably selected from the group consisting of xanthan gum, veeguni, a polyacrylate compound (preferably a crosslinked polyacrylic acid polymer), a bentonite clay type thickener, a carageenan based thickener and silicon oxide. The formulation may comprise one or more of the listed thixotropes in any appropriate relative amount depending upon the desired thixotropic properties of the formulation.

When the thixotrope is xanthan gum, it is preferred that the formulation contains about 0.05 to I % w/w xanthan gum, more preferably about 0.1 to 0.5 % w/w xanthan gum.

When the thixotrope is veegum, it is preferred that the formulation contains about 0.1 to 5 % w/w veegum, more preferably about 1 to 2.5 % w/w veegum.

When the thixotrope is a polyacrylate compound, it is preferred that the formulation contains about 0.05 to 0.5 % w/w of the polyacrylate compound, more preferably about 0.08 to 0.3 % w/w of the polyacrylate compound, and most preferably about 0.1 to 0.2 % w/w of the polyacrylate compound.

When the thixotrope is silicon oxide, it is preferred that the formulation contains about 2.5 to 5.0 % w/w silicon oxide, more preferably about 3 to 4 % w/w silicon oxide.

More preferably the thixotrope is selected from the group consisting of a Carbopol (registered trade mark of Noveon IP Holdings Corp) polymer and a Coatex polymer.

It is particularly preferred that the thixotrope is Carbopol ETD 2623 or Coatex DV866. In a particularly preferred embodiment of the formulation forming the first aspect of the present invention the formulation contains about 0.12 % w/w of Carbopol ETD 2623.

The formulation of the present invention is particularly suitable for spray or "squirt" application on to a surface. It is preferred that a spray volume of about 0.1 to 0.5 ml of the formulation of the present invention when sprayed on to an upright surface from a distance of around 10 to 20 cm provides an even spray pattern of the gelled formulation which exhibits negligible creep. It will be appreciated that where the formulation is to be provided in a form suitable for "squirt" application on to a surface the formulation will generally include a greater amount of thixotrope to thicken the formulation so that it still exhibits negligible creep when applied to the surface.

The formulation may exhibit a viscosity of about 200 to 1000 cps at 20 C measured using a Brookfield RV Viscometer/Rheometer with a No. 21 spindle at a speed of 50 rpm. More preferably the formulation exhibits a viscosity of about 450 to 750 cps at C measured using a Brookfield RV Viscometer/itheometer with a No. 21 spindle at a speed of 50 rpm. Most preferably the formulation exhibits a viscosity of about 550 to 650 cps at 20 C measured using a Brookfield RV Viscometer/Rheometer with a No. 21 spindle at a speed of 50 rpm. It will be appreciated that the viscosity of the formulation when standing on the surface (i.e. when under little or no shear) will be significantly higher than the viscosities quoted above.

Preferably the formulation possesses a pH of around neutrality. The pH may be about 6 to 8, more preferably about 6 to 7.

Where appropriate the formulation may comprise at least one further compound selected from the group consisting of a detergent, a solubiliser, a biocide and a dye.

The formulation preferably comprises sufficient detergent/solubiliser to ensure the formulation of the present invention is at least substantially clear. It may not be necessary to include any detergent or solubiliser in formulations which are already sufficiently clear for their intended use without a detergentlsolubiliser present.

The formulation preferably comprises greater than or equal to about 0.05 % w/w of a biocide, more preferably greater than or equal to about 0.1 % w/w of a biocide. The upper limit for the amount of biocide which may be provided in the formulation of the present invention is determined by the biocidal activity of the particular biocide used (since activity varies from one biocide to another) in conjunction with the maximum amount permissible under safety guidelines for consumer products. Most preferably the formulation contains about 0.2 % w/w of a biocide. A preferred biocide is an isothiazolone, such as Acticide MBS (Thor Specialities (UK) Limited), which is preferably provided in the formulation of the present invention in an amount of about 0.2 % w/w.

Preferably the formulation comprises greater than or equal to about 0.0001 % w/w of at least one dye. More preferably the formulation comprises about 0.000 1 to 1 % w/w of a dye or dyes. Still more preferably the formulation comprises about 0.0002 to 0.5 % w/w of a dye or dyes. Most preferably the formulation comprises about 0.0003 % w/w of a dye. The dye is preferably an Acid dye. Preferred dyes include Acid Blue and Acid Yellow, particularly Acid Blue 9 and Acid Yellow 17, which may be appropriately combined to provide the formulation with a green colouration.

In a preferred embodiment of the present invention the formulation comprises about 0.0003 % w/w Acid Blue 9 and about 0.0013 % w/w Acid Yellow 17.

It is particularly preferred that the formulation which is the subject of the second, third, fourth and fifth aspects of the present invention is the formulation as hereinbefore described in relation to the first aspect of the present invention.

The invention will be further described by way of example only with reference to the following non-limiting Example and Figures in which: Figure 1 is a graphical representation of the results of a panel odour evaluation for an untreated bin and a bin treated with a formulation according to the present invention in which each bin contained soiled nappies; and Figure 2 is a graphical representation of the results of a panel odour evaluation for an untreated bin and a bin treated with a formulation according to the present invention in which each bin contained cooked eggs and raw onions.

EXAMPLE

A formulation according to a preferred embodiment of the present invention was prepared having the composition set out below in Table I. Compound % w/w Carbopol ETD 2623 0.12 Biocide 0.20 Perfume 2.00 Dye 0.0003 Water Balance to 100

Table 1

At ambient temperature the above formulation exhibits sufficiently low viscosity under shear such that it can be sprayed through a standard trigger/pump spray applicator on to an upright surface, such as the inner surface of a waste receptacle.

Upon contact with the surface the spray forms a gel of sufficiently high viscosity such that the gelled formulation exhibits negligible creep during the period of time over which the perfume is released (at least around 7 days, but can vary depending on surrounding conditions, e.g. air flow).

The formulation set out above in Table I was tested as follows for its efficacy in neutralising/masking typical odours.

PANEL TEST

Two variations of household waste type odours were created in standard swing bins in duplicate. Each of the bins was pre-lined with a clean swing bin liner. For each of the bin content types, one bin was left untreated as a control and the second was treated with two squirts of the formulation (as set out in Table 1) to each of the four sides at the top inner surface of the bin liner. Each of the bins was left for 4 hours prior to the first odour panel evaluation. The bins were then left for a further 48 hours or 72 hours prior to a second panel test.

INDIVIDUAL DUPLICATE BIN CONTENTS

Soiled Nappies Cooked eggs and raw onions

PRODUCT APPLICATION TIMES PRIOR TO PANEL TEST EVALUATION

Soiled Nappies 4 hrs 72 hrs Cooked eggs and raw onions 4 hrs 48 hrs

ODOUR EVALUATION BY PANELLISTS

The panel test was performed blind on the unmarked duplicate sets of swing bins.

For each duplicate set of bins containing a particular type of waste ten panellists were asked to smell inside the bins and then score the content odour for strength and pleasantness.

PANEL SCORING

ODOUR STRENGTH

Very Weak Weak Slightly Neither Weak Slightly Strong Very Strong _________ _________ Weak Or Strong Strong _________ 1 2 3 4 5 6 7

PLEASANTNESS OF ODOUR

Very Unpleasant Slightly -Neither Slightly Pleasant Very Unpleasant Unpleasant Pleasant Or Pleasant Pleasant _______ _______ ________ Unpleasant _______ 1 2 3 4 5 6 7

RESULTS

SOILED NAPPIES

Time From 4 hours Application Bin Control Inventive Formulation Character Strength Pleasantness Strength Pleasantness Mean Score 4.8 2.3 5.4 6.2 Time From 72 hours Application Bin Control Inventive Formulation Character Strength Pleasantness Strength Pleasantness Mean Score 6.3 1.7 5.5 4.2

Table 2

ONION AND EGG

Time From 4 hours Application Bin Control Inventive Formulation Character Strength Pleasantness Strength Pleasantness Mean Score 6.5 3 4. 9 5.1 Time From 48 hours Application Bin Control Inventive Formulation Character Strength Pleasantness Strength Pleasantness Mean Score 5.2 3.8 3.8 5.5

Table 3

The above results are represented graphically in Figures 1 and 2.

CONCLUSIONS

Both forms of waste material tested were perceived by the panel as slightly unpleasant /unpleasant in the control bins with the soiled nappies being significantly For the egg and onion bins, odour strength decreased over time and the level of unpleasantness appears to improve proportionally but still not to a level that was considered pleasant. The soiled nappy bins increased in strength and reduced in pleasantness over time.

In both cases the bins treated with the formulation according to the present invention (as set out in Table 1) were perceived as neutralising the unpleasant odours from the waste materials leaving a pleasant residual odour both initially and over time.

Claims

CLAIMS

1. A formulation for spray application to a surface, the formulation comprising greater than or equal to about 1 % w/w of a perfume compound and a sufficient amount of a thixotrope such that the formulation, once applied to the surface, exhibits negligible creep.

2. A formulation according to claim 1, wherein the formulation comprises greater than or equal to about 2 % w/w of the perfume compound.

3. A formulation according to claim I, wherein the formulation comprises about 1 to 20 % w/w of the perfume compound.

4. A formulation according to claim 1, wherein the formulation comprises about 2 to 15 % w/w of the perfume compound.

5. A formulation according to any preceding claim, wherein the perfume compound is selected from the group consisting of a synthetic fragrance compound, a green fragrance compound, a floral fragrance compound, a herbal spice fragrance compound and an oriental fragrance compound.

6. A formulation according to any preceding claim, wherein the formulation, once applied to the surface, exhibits substantially no creep.

7. A formulation according to any on of claims 1 to 5, wherein the formulation, once applied to the surface, exhibits no creep.

8. A formulation according to any preceding claim, wherein the formulation comprises greater than or equal to about 0.05 % w/w of the thixotrope.

9. A formulation according to any one of claims 1 to 7, wherein the formulation comprises greater than or equal to about 0.1 % wlw of the thixotrope.

10. A formulation according to any one of claims I to 7, wherein the formulation comprises about 0.05 to 5 % w/w of the thixotrope.

11. A formulation according to any one of claims 1 to 7, wherein the formulation comprises about 0.05 to 2 % w/w of the thixotrope.

12. A formulation according to any preceding claim, wherein the thixotrope is selected from the group consisting of xanthan gum, veegum, a polyacrylate compound and silicon oxide.

13. A formulation according to any one of claims 1 to 11, wherein the thixotrope is selected from the group consisting of Carbopol ETD 2623 and Coatex DV866.

14. A formulation according to any preceding claim, wherein the formulation exhibits a viscosity of about 200 to 1000 cps at 20 C measured using a Brookfield RV ViscometerfRheometer with a No. 21 spindle at a speed of 50 rpm.

15. A formulation according to any one of claims I to 13, wherein the formulation exhibits a viscosity of about 450 to 750 cps at 20 C measured using a Brookfield RV Viscometer/Rheometer with a No. 21 spindle at a speed of 50 rpm.

16. A formulation according to any preceding claim, wherein the formulation possesses a pH of about 6 to 8.

17. A formulation according to any one of claims I to 15, wherein the formulation possesses a pH of about 6 to 7.

18. A formulation according to any preceding claim, wherein the formulation comprises at least one further compound selected from the group consisting of a detergent, a solubiliser, a biocide and a dye.

19. A formulation according to any one of claims 1 to 17, wherein the formulation comprises sufficient detergent or solubiliser to ensure the formulation is at least substantially clear.

20. A formulation according to any one of claims I to 17 or 19, wherein the formulation comprises greater than or equal to about 0.05 % w/w of a biocide.

21. A formulation according to any one of claims I to 17, 19 or 20, wherein the formulation comprises greater than or equal to about 0. 000 1 % w/w of a dye.

22. A slow release perfume formulation for spray application to a surface, the formulation comprising greater than or equal to about I % w/w of a perfume compound and a sufficient amount of a thixotrope such that the formulation, once sprayed on to the surface, exhibits negligible creep.

23. A method for producing a formulation for spray application to a surface, the formulation comprising greater than or equal to about I % wfw of a perfume compound and a sufficient amount of a thixotrope such that the formulation, once applied to the surface, exhibits negligible creep, wherein the method comprises combining greater than or equal to about I % w/w of the perfume with said sufficient amount of the thixotrope to provide said formulation.

24. A method according to claim 23, wherein the formulation is in accordance with any one of claims 1 to 22.

25. A method for providing a slow release perfume formulation on a surface, wherein the method comprises spraying the formulation according to any one of claims I to 22 on to the surface such that the formulation forms a gel on the surface, the gel being of sufficiently high viscosity so that the formulation on the surface exhibits negligible creep.

26. Use of the formulation according to any one of claims I to 22 for the slow release to a surrounding environment of the perfume compound comprised in the formulation.